Vehicle thermal management system and control method for the same

Patent metadata

Field	Value
Publication number	US-2016347150-A1
Application number	US-201514721411-A
Country	US
Kind code	A1
Filing date	May 26, 2015
Priority date	May 26, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

A thermal management system includes a coolant pump, high-voltage electric heater (HEH) for heating the coolant, a heater core, a blower directing air to the heater core, a cabin heater valve (CHV), sensors, and a controller. The CHV has an Engine Bypass position blocking coolant flow from the HEH into the engine, and an Engine Link position directing coolant from the HEH into the engine. In a method, the sensors measure engine outlet coolant temperature (ECT), inlet coolant temperature (ICT) to the HEH, inlet air temperature into the heater core, and outlet air temperature from the heater core. The controller calculates a target coolant temperature (TCT) value as a function of the air temperatures and mass flow rates, and controls the CHV via position control signals such that the CHV is switched between the Engine Link position and the Engine Bypass position when ICT equals the calculated TCT value.

First claim

1 . A thermal management system for a vehicle having an engine, the thermal management system comprising:
a pump operable for circulating coolant; a high-voltage electric heater (HEH) in fluid communication with the pump, operable for heating the coolant, and having a coolant outlet; a heater core having a coolant inlet in fluid communication with the coolant outlet of the HEH; a blower which directs air to the heater core; a three-way cabin heater valve (CHV) responsive to position control signals and having an Engine Bypass position which blocks a flow of the coolant from the HEH into the engine, and an Engine Link position which directs the flow of the coolant from the HEH into the engine; first, second, third, and fourth temperature sensors which respectively measure an engine outlet coolant temperature (ECT), an inlet coolant temperature (ICT) to the HEH, an inlet temperature of the air into the heater core, and an outlet temperature of the air from the heater core; and a controller in communication with the temperature sensors and programmed to calculate a target coolant temperature (TCT) value as a function of the inlet air temperature, the outlet air temperature, and mass flow rates of the air and the coolant, and to control the CHV via the position control signals such that the CHV is switched between the Engine Link position and the Engine Bypass position when the inlet coolant temperature (ICT) equals the calculated target coolant temperature (TCT) value, thereby balancing cabin heating demand and waste heat utilization of the engine.

2 . The system of claim 1 , wherein the function is:

TCT
=

(

T
IA

+

T
OA

-

T
IA

ɛ

)

-

(

m
.



c
p

)


a

(

m
.



c
p

)


c



(

T
OA

-

T
IA

)

and wherein T IA and T OA are the outlet and inlet air temperatures, respectively, ε is the efficiency of the heater core, and ({dot over (m)}c p ) a and ({dot over (m)}c p ) c are the heat capacity rates of air and coolant, respectively.

3 . The system of claim 1 , wherein the controller is programmed to maintain the Engine Bypass position when the calculated target coolant temperature (TCT) value and the engine outlet coolant temperature (ECT) do not exceed the inlet coolant temperature (ICT) to the HEH.

4 . The system of claim 1 , wherein the controller is programmed to command the CHV to the Engine Link position when the calculated target coolant temperature (TCT) value exceeds the inlet coolant temperature (ICT) and the engine outlet coolant temperature (ECT) exceeds the calculated target coolant temperature (TCT) value.

5 . The system of claim 1 , wherein the controller is programmed to command the CHV to the Engine Link position in response to a selected mode prioritizing cabin heating of the vehicle when the calculated target coolant temperature (TCT) value exceeds the inlet coolant temperature (ICT), the engine outlet coolant temperature (ECT) exceeds the inlet coolant temperature (ICT) and does not exceed the calculated target coolant temperature (TCT) value, and a speed of the engine exceeds a calibrated engine speed.

6 . The system of claim 1 , wherein the controller is programmed to command the CHV from the Engine Link position to the Engine Bypass position if the HEH is running above a calibrated power threshold for a calibrated duration.

7 . The system of claim 1 , wherein the controller is programmed to command the CHV from the Engine Link position to the Engine Bypass position if the HEH is running below a calibrated power threshold, calculated target coolant temperature (TCT) value exceeds the engine outlet coolant temperature (ECT), and a speed of the engine is below a calibrated engine speed.

8 . A method for use in a thermal management system for a vehicle having an engine, the thermal management system including a coolant pump, a high-voltage electric heater (HEH) in fluid communication with the coolant pump, a heater core in fluid communication with the HEH, a blower which directs air to the heater core, a three-way cabin heater valve (CHV) responsive to position control signals and having an Engine Bypass position which blocks a flow of the coolant from the HEH into the engine, and an Engine Link position which directs the flow of the coolant from the HEH into the engine, first, second, third, and fourth temperature sensors, and a controller, the method comprising:
receiving an engine outlet coolant temperature (ECT), an inlet coolant temperature (ICT) to the HEH, an inlet temperature of the air into the heater core, and an outlet temperature of the air from the heater core from the respective first, second, third, and fourth temperature sensors; calculating a target coolant temperature (TCT) value as a function of the received inlet air temperature, the outlet air temperature, and mass flow rates of the air and the coolant; and controlling a three-way cabin heater valve (CHV) having an Engine Bypass position which blocks a flow of the coolant into the engine from a high-voltage electric heater (HEH), and an Engine Link position which directs the flow of the coolant from the HEH into the engine, via position control signals from a controller such that the CHV is switched between the Engine Link position and the Engine Bypass position when the inlet coolant temperature (ICT) equals the calculated target coolant temperature (TCT) value, thereby balancing cabin heating demand and waste heat utilization of the engine.

9 . The method of claim 8 , wherein the function is:

TCT
=

Assignees

• Gm Global Tech Operations Llc

Inventors

• Kakade Rupesh S
• Mer Prashant
• Iyer Vish S
• Carlson Michael H

Classifications

• F01P3/02

  Arrangements for cooling cylinders or cylinder heads · CPC title

• B60H1/004

  for vehicles having a combustion engine and electric drive means, e.g. hybrid electric vehicles · CPC title

• B60H1/034

  from the cooling liquid of the propulsion plant and from an electric heating device · CPC title

• B60H1/00885 Primary

  Controlling the flow of heating or cooling liquid, e.g. valves or pumps (B60H1/00899 takes precedence; constructions of valves B60H1/00485) · CPC title

• B60H1/00764

  the input being a vehicle driving condition, e.g. speed (B60H1/00828, B60H1/00864 take precedence) · CPC title